1. Field of the Invention
This invention relates generally to semiconductor processing, and more particularly to semiconductor chip packaging incorporating passive devices and to methods of manufacturing the same.
2. Description of the Related Art
All integrated circuits require electrical power to operate, and packaged integrated circuits are no exception. Power is normally delivered to integrated circuits via a power supply and some form of power delivery network. Although currently-available power supplies are designed to supply stable voltages, the actual power delivered to integrated circuits can contain significant amounts of noise. There are many sources of noise, such as voltage fluctuations caused by other devices coupled to the power supply, electromagnetic interference and other causes.
Conventional packaged integrated circuits typically include a semiconductor chip mounted on a carrier substrate. The carrier substrate is configured to mount to a printed circuit board, such as a motherboard or card. The typical conventional carrier substrate includes an interconnect system that is made up of multiple layers of conductor planes or traces tied vertically by plural vias. Input/output pads on the die side of the carrier substrate connect to the die and input/output pads on the underside of the carrier substrate connect to the printed circuit board. A ball grid array, a land grid array or pin grid array is used to electrically connect the underside input/output pads to the printed circuit board.
To address issues associated with power supply noise, conventional semiconductor chip packages use decoupling capacitors. Many of these decoupling capacitors are mounted to the carrier substrate. In one conventional variant, the decoupling capacitors are mounted to the die side of the carrier substrate around the periphery of the die. In another conventional variant, the decoupling capacitors are mounted to the underside of the carrier substrate. In the first conventional variant, the electrical pathways from a given underside input/output pad to a die side decoupling capacitor can be large enough to diminish the effectiveness of the decoupling capacitor as a filter. The same may be true for the second conventional variant since the undermounted capacitors are not tied directly to the printed circuit board, but instead rely on the pads and other metallization structures within the carrier substrate to establish connections with the printed circuit board.
The present invention is directed to overcoming or reducing the effects of one or more of the foregoing disadvantages.